The invention relates to steering shaft assemblies and, more particularly to a telescopically adjustable steering shaft assembly for a vehicle.
Vehicles are commonly provided with a steering column assembly in which the upper portion, which carries the steering wheel, is arranged for axial adjustment to enable selective telescopic positioning of the steering wheel through a limited range. This arrangement has been found to be exceptionally advantageous in accommodating vehicle operators of varying stature. The telescoping feature can also be utilized to allow collapse of the steering column in the event of a crash.
Telescoping steering shafts can employ multi-tooth splines to rotationally link the inner and outer shafts while providing for telescoping movement in the axial direction. In some configurations, a tubular female sleeve surrounds a splined shaft with a plastic over-molded feature between the inner and outer shafts. Although such over-mold configurations can be reliable and effective, they can be expensive to produce and require a high degree of manufacturing complexity. Additionally, acceptable telescoping loads can be difficult to achieve and maintain.